The Pirates of the Burning Sea official site has announced that, to help with some ongoing issues, all servers will be subject to a regularly scheduled service downtime. This downtime will occur twice a week, and should only be a server restart, meaning you can log back on and resume looting and plundering within about 20 minutes if all goes well.
So far, we know that the downtimes will take place on Tuesdays and Fridays at 8:30AM GMT for North American and European servers -- times for the Australian server will be listed shortly. It has been said that the restarts can be moved around a bit to accommodate Port Battles, which is a very nice touch and shows quite a level of involvement from Flying Lab Software on a server-specific basis. They hope that the regular restart situation will be temporary, but it's good to see that they will try to soften the blow in the meantime.